US Law Shield Clears Up Where You Can/Can’t Carry A Gun In Oklahoma
You would think that firearms laws were pretty cut & clear, but there is enough wiggle room in the gray area of the law. The question most posed is "Can I still carry if they have a bar?" For instance, if you want to hop out to dinner at the steak house, and it has a bar inside, are you legally required to disarm yourself? The law is somewhat interpretive and ambiguous.
In Oklahoma, it's illegal to carry your firearm into an establishment where alcohol is sold as the primary purpose of business and trade. Liquor stores and stand alone bars are the obvious, but that doesn't clear other establishments. I used to run a bait & tackle shop in Northern Oklahoma, but it also had a bar inside. We sold low-point beer, but as our purpose and primary source of revenue was selling minnows and fishing gear. You can see that line blur a little bit in that situation. Same goes for other establishments.
While the best answer would be to consult a lawyer versed in this particular area of legislation, a better suggestion might be to err on the side of caution. If the food is good enough to leave your firearm in the car, by all means... and on that same note, if the food is not, it would be more prudent to choose a better restaurant that conforms to the legalities of your license.